1. Field of the Invention
The present invention relates to a technique for shielding an electric field.
2. Description of the Background Art
In a semiconductor device having a semiconductor chip covered with a solid or gel resin, ions as impurities in the resin move by the applied voltage, exhibiting polarization. In this case, a voltage produced by the ions exceeds the threshold voltage of elements forming an integrated circuit and a channel for carrying leakage current is formed between adjacent elements, which prevents the elements from carrying out their functions. Such a problem is pointed out in, for example, Japanese Patent Application Laid-open No. 11-204733.
Further, a technique for reducing electromagnetic noise which is emitted from an interconnect layer and gets into another circuit portion is disclosed in, for example, Japanese Patent Application Laid-open Nos. 5-47767 and 8-274167.
However, if the interconnect layer is enclosed by a conductive material which is continuous as viewed in section and which is supplied with a fixed potential, a voltage applied to an insulating material provided between the interconnect layer and the conductive material increases with increasing applied voltage to the interconnect layer, which results in a tendency to easily cause dielectric breakdown in the insulating material.